Near-field microwave diagnostics with nonlinear-optical sensors

The concept and implementation of a near-field microwave measurement system that relies on the Pockels effect in fiber-coupled, semi-insulating GaAs probes to acquire polarization-sensitive maps of electric-field patterns in close proximity to antenna arrays, integrated circuits, and packaged components, is presented. The evolution of the electro-optic field-mapping technique, which has subsequently addressed magnetic-field characterization via magneto-optic sensing and temperature measurement through semiconductor band-gap modulation, will also be discussed. The use of emerging materials, such as diluted magnetic semiconductors, is also considered.